[Bug]-ish including addon created empty object in config.module.rules

[Jackbennett]

Describe the bug

adding "@storybook/addon-postcss",

To addons in .storybook/main.js

module.exports = {
  addons: [
    "@storybook/addon-essentials",
    "@storybook/addon-links",

  ],

Created an empty object in config.module.rules

My config has const fileLoaderRule = config.module.rules.find((r) => r.test.test(".svg")); to edit something unrelated, but adding an empty object made it explode.

Expected behaviour

Maybe don't add an empty object to config.module.rules

Environment

• OS: ubuntu 18.04
• Node.js version: 16.10
• NPM version: 7.24.2

Additional context

just console.log the config.module.rules array with and without the addon.